Heat olive oil in a large pot over medium heat. Add chopped onion and cook until soft and translucent. Stir in garlic and cook briefly until fragrant, making sure it doesn’t burn.
Add carrots, celery, and zucchini to the pot. Cook for a few minutes until they begin to soften. This helps release their natural sweetness and enhances the overall flavor.
Sprinkle in cumin, coriander, paprika, cinnamon, and turmeric. Stir well to coat the vegetables evenly. Let the spices toast slightly to release their aroma and deepen the flavor.
Pour in vegetable broth and diced tomatoes. Add chickpeas and mix everything together. Bring the soup to a gentle boil, then reduce heat and let it simmer.
Stir in couscous and let it cook directly in the soup. It will absorb the flavorful broth and become tender. This step thickens the soup slightly and makes it heartier.
Season with salt, pepper, and lemon juice. Taste and adjust seasoning if needed. Let the soup sit for a few minutes before serving to allow flavors to blend.